source: source/ariba/communication/modules/transport/protlib/timer.cpp@ 4987

/// ----------------------------------------*- mode: C++; -*--

/// @file timer.cpp

/// Software timer interface

/// ----------------------------------------------------------

/// $Id: timer.cpp 2549 2007-04-02 22:17:37Z bless $

/// $HeadURL: https://svn.ipv6.tm.uka.de/nsis/protlib/trunk/src/timer.cpp $

// ===========================================================

//                      

// Copyright (C) 2005-2007, all rights reserved by

// - Institute of Telematics, Universitaet Karlsruhe (TH)

//

// More information and contact:

// https://projekte.tm.uka.de/trac/NSIS

//                      

// This program is free software; you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation; version 2 of the License

//

// This program is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

//

// You should have received a copy of the GNU General Public License along

// with this program; if not, write to the Free Software Foundation, Inc.,

// 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

//

// ===========================================================

/** @ingroup timer 

 * You can create a software timer and attach a callback object to it.

 * Timers are only accessed through their TimerManager and timer ID.

 * timer managers are thread-safe.

 *

 * Timers are stored in an ordered list to ease checking for elapsed timers.

 * Additionally, their IDs are kept in a hash_map, so a pointer to a

 * timer object can be obtained very fast.

 */



//#define DEBUG_TIMER



#include <errno.h>



#include "cleanuphandler.h"

#include "timer.h"

#include "logfile.h"



namespace protlib {



/** @addtogroup timer Timer

 * @{

 */



  using namespace log;



static inline 

void 

normalize_timespec(struct timespec& ts) 

{

  while (ts.tv_nsec>=1000000000) {

    ts.tv_sec++;

    ts.tv_nsec -= 1000000000;

  } // end while

  if (ts.tv_sec<0) ts.tv_sec = 0;

  if (ts.tv_nsec<0) ts.tv_nsec = 0;

} // end normalize



/**

 *  fills in timespec with sec+msec, msec may be larger than 999!

 */

static inline 

void 

fill_timespec(struct timespec& ts, int32 sec, int32 msec) 

{

  if (sec<0) sec = 0;

  if (msec<0) msec = 0;

  ts.tv_sec = sec + (msec/1000);

  ts.tv_nsec = (msec%1000)*1000000;

  normalize_timespec(ts);

} // end fill_timespec



static inline 

void 

add_timespecs(struct timespec& ts1, struct timespec& ts2, struct timespec& res) {

  res.tv_sec = ts1.tv_sec + ts2.tv_sec;

  res.tv_nsec = ts1.tv_nsec + ts2.tv_nsec;

  normalize_timespec(res);

} // end add_timespecs



static inline void gettimeofday_timespec(struct timespec& ts) {

        struct timeval now = {0,0};

        gettimeofday(&now,NULL);

        ts.tv_sec = now.tv_sec;

        ts.tv_nsec = now.tv_usec*1000;

} // end gettimeofday_timespec



/** Initialize a TimerManager object. */

TimerManager::TimerManager() 

{

  pthread_mutexattr_init(&mutex_attr);

#ifdef _DEBUG

  pthread_mutexattr_settype(&mutex_attr,PTHREAD_MUTEX_ERRORCHECK);

#else

  pthread_mutexattr_settype(&mutex_attr,PTHREAD_MUTEX_NORMAL);

#endif



  pthread_mutex_init(&mutex,&mutex_attr);

  pthread_cond_init(&cond,NULL);



  Log(DEBUG_LOG,LOG_NORMAL, "Timer", "Creating TimerManager");

} // end constructor TimerManager



/** Destroy TimerManager. */

TimerManager::~TimerManager() {

#ifndef _NO_LOGGING

        int num = cleanup();

#else

        cleanup();

#endif

        DLog("Timer", "Destroying TimerManager with " << num << " timers");

        pthread_cond_destroy(&cond);

        pthread_mutex_destroy(&mutex);

        pthread_mutexattr_destroy(&mutex_attr);

} // end destructor TimerManager



/** Start a timer relative to current time.

 * @return ID of the new timer.

 */

timer_id_t 

TimerManager::start_relative(TimerCallback* tc, int32 sec, int32 msec, timer_callback_param_t tcp) 

{

  struct timespec timeofday = {0,0};

  struct timespec reltime = {0,0};

  struct timespec alarm = {0,0};

  timer *t = NULL;

  timer_id_t result = 0;

  fill_timespec(reltime,sec,msec);

  // calculate absolute alarm time

  gettimeofday_timespec(timeofday);

  add_timespecs(timeofday,reltime,alarm);       

  // begin critical section

  pthread_mutex_lock(&mutex); // install_cleanup_mutex_lock(&mutex);

  // start timer

  t = new(nothrow) timer(alarm,tc,tcp);

  if (t) {

    result = t->id;

    // insert into list

    insert_into_list(t);

    // insert into hash

    hashmap[result] = t;

    // wake up threads

    pthread_cond_signal(&cond);

  } else {

    Log(ERROR_LOG,LOG_CRIT, "Timer", "TimerManager::start_relative() is unable to create timer object");

  } // end if t

  // end critical section

  pthread_mutex_unlock(&mutex); // uninstall_cleanup(1);

  return result;

} // end start_relative



/** Start an absolute timer.

 * @return ID of the new timer.

 */

timer_id_t 

TimerManager::start_absolute(TimerCallback* tc, int32 sec, int32 msec, timer_callback_param_t tcp) {

  struct timespec alarm = {0,0};

  timer *t = NULL;

  timer_id_t result = 0;

  fill_timespec(alarm,sec,msec);

  // begin critical section

  pthread_mutex_lock(&mutex); // install_cleanup_mutex_lock(&mutex);

  // start timer

  t = new(nothrow) timer(alarm,tc,tcp);

  if (t) {

    result = t->id;

    // insert into list

    insert_into_list(t);

    // insert into hash

    hashmap[result] = t;

    // wake up threads

    pthread_cond_signal(&cond);

  } else {

    Log(ERROR_LOG,LOG_CRIT, "Timer", "TimerManager::start_absolute() is unable to create timer object");

  } // end if t

  // end critical section

  pthread_mutex_unlock(&mutex); // uninstall_cleanup(1);

  return result;

} // end start_absolute



/** Restart a timer and set the alarm relative to the current time.

 * The timer must exist and go off in the future.

 * @return true on success, false otherwise.

 */

bool 

TimerManager::restart_relative(timer_id_t id, int32 sec, int32 msec) 

{

  struct timespec timeofday = {0,0};

  struct timespec reltime = {0,0};

  struct timespec alarm = {0,0};

  timer *t = NULL;

  bool result = false;

  timer_hashmap_it_t hit;

  fill_timespec(reltime,sec,msec);

  // calculate absolute alarm time

  gettimeofday_timespec(timeofday);

  add_timespecs(timeofday,reltime,alarm);       

  // begin critical section

  pthread_mutex_lock(&mutex); // install_cleanup_mutex_lock(&mutex);

  // try to get timer with given ID

  if ((hit=hashmap.find(id))!=hashmap.end()) t = hit->second; else t = NULL;

  if (t) {

    // delete from list, set new alarm and insert

    delete_from_list(t);

    t->time = alarm;

    insert_into_list(t);

    // wake up threads

    pthread_cond_signal(&cond);

    result = true;

  } else {

    Log(DEBUG_LOG,LOG_NORMAL, "Timer", "TimerManager::restart_relative() is unable to restart timer " << id);

  } // end if t

  pthread_mutex_unlock(&mutex); // uninstall_cleanup(1);

  return result;

} // end restart_relative





/** Restart a timer and set the alarm to an absolute time.

 * The timer must exist and go off in the future.

 * @return true on success, false otherwise.

 */

bool 

TimerManager::restart_absolute(timer_id_t id, int32 sec, int32 msec) 

{

  struct timespec alarm = {0,0};

  timer *t = NULL;

  bool result = false;

  timer_hashmap_it_t hit;

  fill_timespec(alarm,sec,msec);

  // begin critical section

  pthread_mutex_lock(&mutex); // install_cleanup_mutex_lock(&mutex);

  // try to get timer with given ID

  if ((hit=hashmap.find(id))!=hashmap.end()) t = hit->second; else t = NULL;

  if (t) {

    // delete from list, set new alarm and insert

    delete_from_list(t);

    t->time = alarm;

    insert_into_list(t);

    // wake up threads

    pthread_cond_signal(&cond);

    result = true;

  } else {

    Log(DEBUG_LOG,LOG_NORMAL, "Timer", "TimerManager::restart_relative() is unable to restart timer " << id);

  } // end if t

  pthread_mutex_unlock(&mutex); // uninstall_cleanup(1);

  return result;

} // end restart_absolute



/** Stop the given timer. */

bool TimerManager::stop(timer_id_t id) 

{

  timer *t = NULL;

  bool result = false;

  timer_hashmap_it_t hit;

  // begin critical section

  pthread_mutex_lock(&mutex); // install_cleanup_mutex_lock(&mutex);

  if ((hit=hashmap.find(id))!=hashmap.end()) {

    t = hit->second;

    // erase from hashmap

    hashmap.erase(hit);

  } else t = NULL;

  // delete from list if t exists

  if (t) {

    delete_from_list(t);

    // wake up threads

    pthread_cond_signal(&cond);

    result = true;

  } else {

    Log(DEBUG_LOG,LOG_NORMAL, "Timer", "TimerManager::stop() is unable to stop timer " << id);

  } // end if t

  pthread_mutex_unlock(&mutex); // uninstall_cleanup(1);

  return result;

} // end stop



/** Check if timers have elapsed and call their callbacks.

 * @return the number of elapsed timers. 

 */

uint32 

TimerManager::check_timers() 

{

  timer *elapsed;

  pthread_mutex_lock(&mutex); // install_cleanup_mutex_lock(&mutex);

  elapsed = collect_elapsed();

  pthread_mutex_unlock(&mutex); // uninstall_cleanup(1);

        return process_elapsed();

} // end check_timers



/** Like check_timers() but waits msec milliseconds for a timer to elapse. */

uint32 

TimerManager::check_timers_wait(int32 msec) 

{

  struct timespec now = {0,0};

  struct timespec reltime = {0,0};

  struct timespec abstime = {0,0};

  timer* elapsed;

  int wait_res = 0;

  fill_timespec(reltime,0,msec);

  gettimeofday_timespec(now);

  // calculate timespec for pthread_cond_timedwait()

  add_timespecs(now,reltime,abstime);

  timer maxwait(abstime,NULL,NULL,false);

  // begin critical section

  pthread_mutex_lock(&mutex); // install_cleanup_mutex_lock(&mutex);

  // look for elapsed timers until timeout

  elapsed = collect_elapsed();

  while ((!elapsed) && (wait_res!=ETIMEDOUT)) {

    // neither timeout nor elapsed timers

    // if there is a timer in the list, wait until it elapses.

    // otherwise wait abstime.

    if (first() && ((*first())<=maxwait)) abstime = first()->time;

    else abstime = maxwait.time;

    // wait for condition or timeout

    wait_res = pthread_cond_timedwait(&cond,&mutex,&abstime);

#ifdef DEBUG_TIMER

    Log(DEBUG_LOG,LOG_NORMAL, "Timer", "TimerManager::check_timers_wait() - timedwait returned " << wait_res << ":" << strerror(wait_res));

#endif

    elapsed = collect_elapsed();

#ifdef DEBUG_TIMER

    if (elapsed)

      Log(DEBUG_LOG,LOG_NORMAL, "Timer", "TimerManager::check_timers_wait() - collect_elapsed() returned " <<  elapsed->id);

#endif

  } // end while !elapsed and !wait_res

  // end critical section

  pthread_mutex_unlock(&mutex); // uninstall_cleanup(1);

  // now either timeout, cancellation or elapsed timers

  return process_elapsed();

} // end check_timers_wait



/** Stop all timers. */

uint32 

TimerManager::stop_all() 

{

  uint32 result = 0;

  pthread_mutex_lock(&mutex); // install_cleanup_mutex_lock(&mutex);

  result = cleanup();

  if (result) {

    // wake up threads

    pthread_cond_signal(&cond);

  } // end if result

  pthread_mutex_unlock(&mutex); // uninstall_cleanup(1);

  return result;

} // end stop_all_timers



/** Stop all timers without locking the mutex.

 * So this can be called safely inside the TimerManager constructor.

 */

uint32 

TimerManager::cleanup() 

{

  uint32 num = 0;

  // clear hashmap

  hashmap.clear();

  

  // delete all timers

  timer *curr= 0;

  while (!active_timerlist.empty())

  {

    if ( (curr= active_timerlist.front()) != 0 )

    {

      delete curr;

      active_timerlist.pop_front();

      num++;

    }

  } // end while

  return num;

} // end cleanup



/** Insert a timer object into the timer list.

 * Timers are stored in an ordered list, so when checking for elapsed timers

 * it's enough to check timers beginning at the front end until one is

 * still running.

 */

inline 

void 

TimerManager::insert_into_list(timer *t) 

{

  timerlist_t::iterator listiter= active_timerlist.begin();

  while(listiter != active_timerlist.end())

  {

    if ( *listiter ) 

    {

      // if current element is greater than *t, leave the loop

      if (!( *(*listiter) <= *t ))

        break;

      

    }

    listiter++;

  } // end for

  active_timerlist.insert(listiter,t);





#ifdef DEBUG_TIMER

        Log(DEBUG_LOG,LOG_NORMAL, "Timer", "TimerManager::insert_into_list() - inserting timer " << t->id << " list now:");

#endif



#ifdef DEBUG_TIMER

  for(timerlist_t::iterator listpiter= active_timerlist.begin();

      listpiter != active_timerlist.end();

      listpiter++)

  {

    Log(DEBUG_LOG,LOG_NORMAL, "Timer", "TimerManager::insert_into_list() - timer list, timer#: " << (*listpiter ? (*listpiter)->id : 0));

  }

#endif



} // end insert_into_list



/** Delete a timer from the ordered timer list. 

 * The timer object is NOT freed because it may be needed for executing its

 * callback or for restarting.

 * The timer objects must be linked correctly, no checking is done.

 */

void 

TimerManager::delete_from_list(timer *t) {



  if (!t) return;



#ifdef DEBUG_TIMER

  Log(DEBUG_LOG,LOG_NORMAL, "Timer", "TimerManager::delete_from_list() - deleting timer " << t->id);

#endif

  timerlist_t::iterator listiter= find(active_timerlist.begin(),active_timerlist.end(),t);

  if ( listiter != active_timerlist.end() )

      active_timerlist.erase(listiter);

#ifdef DEBUG_TIMER

  if (first()) 

    Log(DEBUG_LOG,LOG_NORMAL, "Timer", "TimerManager::delete_from_list() - first timer now " << (first() ? first()->id : 0) );

#endif

} // end delete_from_list



/** Collect all elapsed timers in the elapsed_timerlist and delete them already

 * from the hashmap. The timers are deleted in process_elapsed().

 * You must lock the TimerManager mutex before collecting timers.

 * When timers have elapsed, the condition is signaled.

 */

TimerManager::timer* 

TimerManager::collect_elapsed() 

{       

  struct timespec tod;

  gettimeofday_timespec(tod);

  timer now(tod,NULL,NULL,false);



  timerlist_t::iterator currentit = active_timerlist.begin();

  timer* curr= first();

#ifdef DEBUG_TIMER

  if (curr)

    Log(DEBUG_LOG,LOG_NORMAL, "Timer", "TimerManager::collect_elapsed() - first timer is " << curr->id);

#endif



  // search the last timer in list <= now

  while (curr && ((*curr)<=now)) 

  { // current timer is already elapsed

    hashmap.erase(curr->id);

#ifdef DEBUG_TIMER

    Log(DEBUG_LOG,LOG_NORMAL, "Timer", "TimerManager::collect_elapsed() - deleted elapsed timer " << curr->id);

#endif

    // remember it in elapsed list

    elapsed_timerlist.push_back(curr);

    // delete it from the active timer list

    currentit= active_timerlist.erase(currentit);



    curr= (currentit != active_timerlist.end()) ? *currentit : 0;

  } // end while

  // List is ordered, so all timers before currentit are elapsed.



  timer* elapsed = elapsed_timerlist.empty() ? 0 : elapsed_timerlist.front();



  // wake up threads

  if (elapsed) pthread_cond_signal(&cond);

  

  return elapsed;

} // end collect_elapsed



/** Process a list of timers by executing the callback routines and deleting

 * the timer objects. They are NOT deleted from the TimerManager hashmap.

 * The mutex should not be locked when callbacks are executed, because 

 * it is unpossible to start a new timer inside a callback routine when

 * the mutex is still locked.

 * @see collect_elapsed()

 */

uint32 TimerManager::process_elapsed() 

{

  uint32 num = 0;

  timer *tmp = NULL;



  // for every elapsed timer (list should be prepared by collect_elapsed) do_callback()

  for (timerlist_t::iterator elapsed_it= elapsed_timerlist.begin();

       elapsed_it != elapsed_timerlist.end();

       elapsed_it= elapsed_timerlist.erase(elapsed_it))

  {

    // invoke callback function on elapsed timer

    if ( (tmp = *elapsed_it) != 0)

    {

      tmp->do_callback();

      // when callback is finished, delete the stuff

      delete tmp;

      num++;

    }

    // get next elapsed timer

  } // end for

  return num;

} // end process_elapsed



/** Initialize a timer.

 * If get_id is set (default) the timer gets a unique ID, otherwise the ID

 * of the timer is 0.

 */

TimerManager::timer::timer(struct timespec& ts, TimerCallback* tc, timer_callback_param_t tcp, bool get_id) :

  id (0),

  time(ts),

  callback(tc),

  param(tcp)

{

  if (get_id) while (id==0) id = next_id++;

} // end constructor timer



/** This holds the timer ID of the next timer. */

timer_id_t TimerManager::timer::next_id = 1;



/** Check which timer goes off eralier. 

 * The timespec structores of the timers are expected to have correct

 * format.

 */

inline 

bool 

TimerManager::timer::operator<=(const timer& t) {

  if (time.tv_sec == t.time.tv_sec) {

    // Seconds are equal, it depends on nanoseconds.

    return (time.tv_nsec <= t.time.tv_nsec);

  } else {

    // Seconds are not equal, nanoseconds do not matter.

    return (time.tv_sec < t.time.tv_sec);

  }

} // end operator<=



inline 

void 

TimerManager::timer::do_callback() {

  callback->timer_expired(id,param);

} // end do_callback



//@}



} // end namespace protlib